Could any one suggest, how can i integrate ADB devices with katalon studio instead of integrate with Kobition or browser stack (Its too expensive to use for long run) or any alternate ways are there to run free emulators using katalon studio script ??

I think there is currently no *free* devices like that unless you setup your own devices farm by yourself and use it :). That’s why both Kobiton and BrowserStack offer free trial and purchase options because of high efforts in setup and maintenance